Description
Woodward A8516-038
Technical Specifications
- Speed Setting Range: Adjustable via external screw mechanism.
- Drive Rotation: Counterclockwise (standard configuration).
- Rotary Output Torque: Sufficient torque to directly drive turbine steam valves.
- Safety Features: Integrated Overspeed Test Device (OTSD).
Functional Features
- Self-Contained Hydraulics: Integrated shaft-driven oil pump generates necessary hydraulic pressure.
- Direct Valve Actuation: Rotary output shaft connects directly to the turbine’s governor valve.
- Mechanical Speed Sensing: Centrifugal ball head assembly precisely senses turbine rotor speed.
- Fail-Safe Design: Purely mechanical operation ensures continued control during total plant power loss.
Application Scenarios
Ideal for driving industrial compressors, boiler feed pumps, and backup generators in petrochemical, refining, and power generation facilities.
Performance Parameters
- Control Accuracy: Maintains stable speed within mechanical droop limits.
- Reliability: Exceptional mean time between failures due to absence of electronic components.
- Hazardous Area Rating: Safe for use in explosive atmospheres when equipped with OTSD.
Material Composition
Rugged die-cast aluminum TG-17 enclosure protecting precision-machined steel hydraulic spools, springs, and centrifugal weights.
Structural Characteristics
- Housing: Die-cast aluminum for thermal stability and vibration resistance.
- Connections: Mechanical input drive and rotary output terminal shaft.
- Adjustments: External screw for speed set point and droop calibration.
Working Principle
Turbine rotation drives the internal ball head, translating rotational speed into linear mechanical displacement. This displacement acts on a hydraulic servo valve that meters oil to a rotary actuator, adjusting the steam valve to maintain the desired droop speed.
Installation Requirements
- Align the input drive shaft carefully to avoid excessive vibration.
- Connect the output terminal shaft to the steam valve using the specified torque coupling.
- Verify ATEX compliance labeling matches the installation zone.
Usage Precautions
- Regularly test the integrated OTSD to verify overspeed protection.
- Do not exceed the maximum rated speed for the specific model.
- Monitor for hydraulic oil leaks at shaft seals and replace immediately if detected.
